Supercharged engine



United States Patent [72] Inventor: Donald E. Stinebaugh Post Falls, Idaho [21] Application No.: 687,164 [22] Filed: Dec. 1, 1967 [45] Patented: Aug. 4, 1970 [73] Assignee: Power Research and Development,

Inc., Spokane, Washington, a Corp. of Washington [54] SUPERCHARGED ENGINE laims, Drawing Figs. [52] U.S. Cl. 123/75, 123/73, 123/141, 123/119 [51 J Int. Cl F02b 33/26 [50] Field ofSearch l23/75RC, 75CC, 75, 73A2, 73A4, 73, 57A, 57B, 141, 1 19C, [56] References Cited 37Cur$ry UNITED STATES PATENTS 931,976 8/1909 Turner... 123/75CC 1,184,158 5/1916 Beard 123/75CC 1,350,135 8/1920 Berg 123/73A4 1,383,536 7/1921 Davies 123/57A 3,288,123 11/1966 Stinebaugh l23/57A FOREIGN PATENTS 184,177 10/1922 GreatBritainf 123/119C 199,880 7/1923 Great Britain. l23/73A4 341,523 l/l93l Great Britain. 123/73A2 523,270 7/1940 Great Britain. 123/73A2 Primary Examiner- Wendell E. Burns Attorney-Buckhorn, Blore, Klarquist and Sparkman ABSTRACT: A four-cycle, supercharged engine (FIGS. 1 to 6) in which the combustible mixture is turbulated by drawing it into the crankcase through a valve cam chamber and by the crank and is supplied to a dual cylinder through positively driven sleeve valves. Piston type valving is provided and a single piston acts to valve both intake and exhaust. Supercharging is adjustable by a crankcase plug (FIG. 1) adjustably withdrawable from the crankcase, which also is used to relieve compression to facilitate cranking of the engine to start it. In the engine of FIGS. 7 and 8, a carburetor is connected to the crankcase by a check valve, and the crankcase is connected by a check valve to the intake manifold which has a volume at least as great as the displacement of each piston so that a supply of highly compressed air-gasoline mixture is available immediately upon the start of an intake stroke of the piston, A dual or stepped piston has wedge-like head ends to eliminate ping and a booster piston is driven by the crankshaft oppositely tothe stepped piston to add to the supercharging, and the drive of the booster piston is adjustable manually by a spline connection to the booster piston to vary the supercharging. Valving pistons slidable in sleeves operate to connect single ports in the cylinders alternately to intake and exhaust. A camshaft is connected through adjustable spiral gearing to a camshaft drive to provide timing adjustment while the engine is running. A supercharged engine of FIGS. 10 to 14 has an intake manifold of as great a volume as that of each of two pistons, and the manifold is connected by a check valve to a supercharging crankcase. A single sleeve valve is driven by a three lobe, constant diameter cam to effect quick opening and quick closing of intake ports to the two cylinders, and a similar sleeve valve effects exhaust of the two cylinders. A rotary hollow plug is rotated by an actuator driven by the combined action of a throttle controlled link and a manifold pressure controlled link. Rotation of the plug in the same direction successively closes off compartments in the plug from the crankcase to successively increase supercharging.

Patented Aug. 4,1970 3,522,797

DONALD E. STINEBAUGH l/VVE/VTUR BUCKHORM BLORE, KLAROU/ST 8 SPAR/(MAN ATTORNEYS Patented Aug. 4, 1970 Sheet FIG. 2

DONALD E. STRNEBAUGH lNVE/VTOR BUG/(HORN, BLORE, KLAROU/ST 8 SPAR/(MAN Patented Aug. 4, 1970 3,522,797

FIG. 4

.72 FIG 6 DONALD E. STINEBAUGH I BUCKHOR/V, BLORE, KLAROU/ST 8 SPAR/(MAN ATTORNEYS Patented Aug. 4, 1970 3,522,797

Sheet 4 of 6 DONALD E. STINEBAUGH INVENTOR BUG/(HORN, BLORE, KL/JROU/ST 8 SPAR/(MAN ATTORNEYS Patented Aug. 4, 1970 3,522,797

FIGS) DONALD Ev STINEBAUGH BUCKHOEW, BLORE, KLAROU/S 7' 8 SPAR/(MAN A T TOP/11E Y5 Patented Aug. 4, 1970 FIG. 11

FIG. 13

FIG. 14

DONALD E. STINEBAUGH INVENTOR BUG/(HORN, BLORE, KLAROU/S T 8 SPAR/(MAN AT TOR/VEYS US. PATENT 3,522,797 SUPERCHARGED ENGINE DESCRIPTION This invention relates to supercharged engines, and more particularly to engines having selectively variable supercharging.

In high speed supercharged engines of the prior art there is no provision for connecting a large supply of a combustible mixture under supercharged pressure to a cylinder immediately upon opening an intake valve to the cylinder. Also, faster acting valving has been needed and the extent of supercharging and timing has been fixed, usually at the optimum for maximum speed, and no adjustments can be effected while the engines are running. There have been problems ofsurging due to imperfect timing of the valves. There also have been carburetion problems in obtaining thorough mixtures of air and gasoline. Also, for highest efficiency, a high compression ratio is desirable. However, where an engine has a high compres sion ratio, it requires a large force to crank or turn it over to start it either manually or by an electric starter. Problems of detonation or pinging also have been present. It would be desirable to provide in a supercharged engine a large supply of the combustible mixture under high pressure immediately available for intake, fast acting valves, adjustment of the supercharging and timing while the engine is running, improved valve timing, thorough mixing of air and gasoline, and low compression for starting and high compression after it has been started.

An object of the invention is to provide a new and improved four-cycle, supercharged engines.

Another object of the invention is to provide engines having selectively variable supercharging.

A further object ofthe invention is to provide supercharged engines having large volumes of combustible mixtures under high pressures availablekimmediately upon opening of intake valves ofcylinders of the engines.

Another object of the invention is to provide a supercharged engine having a single valve sleeve controlling the ports to two cylinders and driven by a revolved, three lobe, constant diameter cam.

A further object of the invention is to provide supercharged engines having improved valving.

Another object of the invention is to provide supercharged engines in which superchargings are adjustable while the engines are running.

A further object of the invention is to provide a supercharged engine having a single valve supply the intakes of two cylinders.

Another object of the invention is to provide a supercharged engine in which valve timing is adjustable while the engine is running.

A further object of the invention is to provide a supercharged engine which has a booster piston to increase supercharging.

Another object of the invention is to provide a supercharged engine in which a single valve piston acts to control both intake and exhaust.

Another object of the invention is to provide a supercharged engine eliminating pinging.

Another object of the invention is to provide a supercharged engine having thorough mixing of air and gasoline.

Another object of the invention is to provide a high com pression supercharged engine in which the compression is relieved to facilitate starting the engine.

The invention provides supercharged engines in which plug or piston members are adjustable in the crankcases to adjust the supercharging while the engines are running. In one embodiment of the invention the piston member does not move except for the adjustment, in another embodiment of the inventionthe piston member is driven by the crankshaft to increase the supercharging, and in another embodiment of the invention the piston member is adjustable by the combined action of the throttle control and the manifold pressure. In the first-mentioned embodiment, elongated tubular valves connect the crankcase to the cylinders, preferably are driven positively in both directions to insure precise timing, and the crankcase is connected to the carburetor through a camshaft chamber to cause the camshaft to turbulate the mixture. In the second-mentioned embodiment ofthe invention, a camshaft is driven by an adjustable, spiral gearing connection to the crankshaft with a manual actuator to adjust the timing to the optimum while the engine is running and preferably the working pistons have wedge-like head portions to minimize detonation or pinging. The plug or piston members are adjustable to start positions in which supercharging is minimized to reduce the compression ratios to extents permitting hand cranking of the engines, the plug of the engine of one embodiment being adjustable by the combined action of a throttle control and a device responsive to manifold pressure A complete understanding of the invention may be obtained from the following detailed description of four-cycle, supercharged engines forming specific embodiment thereof, when read in conjunction with the appended drawings,in which:

FIGURE 1 is a vertical sectional view of a four-cycle, su percharged engine forming one embodiment of the invention;

FIGURE 2 is a stepped, vertical sectional view taken along line2-2 of FIGURE 1;

FIGURE 3 is a fragmentary, vertical sectional view taken along line 3-3 of FIGURE 1;

FIGURE 4 is an enlarged, vertical sectional view of a valve ofthe engine of FIGURE 1',

FIGURE 5 is an enlarged, horizontal sectional view of the valve of FIGURE 4;

FIGURE 6 is an enlarged fragmentary elevational view taken substantially along line 6-6 of FIGURE 3;

FIGURE 7 is a vertical sectional view of a four-cycle, supercharged engine forming an alternate embodiment of the invention;

FIGURE 8 is an enlarged horizontal sectional view taken along line 8-8 of FIGURE 7;

FIGURE 9 is a vertical sectional view of a four-cycle, supercharged engine forming an alternate embodiment ofthe invention;

FIGURE 10 is a fragmentary, vertical sectional view of the engine of FIGURE 9;

FIGURE ll is an enlarged vertical sectional view taken along line 11-11 of FIGURE 10',

FIGURE 12 is an enlarged elevation view taken along line [2-12 ofFIGURE 11;

FIGURE i3 is an enlarged, substantially horizontal sectional view taken along line 13-13 ofFIGURE 9', and

FIGURE 14 is an enlarged elevation view taken along line 14-14 ofFIGURE l3.

Referring now in detail to the drawings. there is shown therein a supercharged engine forming one embodiment of the invention. The engine includes a block 10, which is a onepiece die casting having an upper cylinder or bore 12 and a lower cylinder or counterbore 14. A one-piece dual piston 16 includes a smaller, upper piston member 18 fitting closely and slidably in the bore 12 and a larger, lower piston member 20 fitting closely and slidably in the counterbore 14. The effective areas of the two piston members are equal, and the effective volumes of the two cylinders 12 and 14 also are equal. The piston member 18 carries piston rings 22, and the piston member 20 carries piston rings 24.

A connecting rod 30 is connected by a wrist pin 32 to the piston 16 and by a bearing 34 to a crank portion 36 of a crankshaft 38 journaled in bearings 40 and 42 (FIGURE 2) carried by the block 10 and a crankcase 44 having a mounting flange 46. Seals 48 and 50 seal the crankshaft, and a flywheel 52 is carried by the crankshaft. An automatic rewind starting mechanism and a combined magneto, breaker point and distributor mechanism 54 are secured to the flywheel end portion of the crankshaft. A gear train including a timing gear 56 keyed to the crankshaft and positioned in the side casing portion 58 of the crankcase drives a driven timing gear 60 keyed to a camshaft 62 journaled in bearings 64 and 66 carried in a valve housing casting 68 secured by cap screws 70 (FIGURE 1 to the crankcase and the block. Capscrews 72 secure flanged lower end 74 of the block to a flanged upper end 76 of the crankcase. An upper portion 78 of the valve housing casting 68 is secured by capscrews 80 (FIG. 3) to the block and the crankcase. Cooling fins 82 are provided on the block, and spark plugs 84 and 86 (FIGURE 1 are mounted respectively in a head 88 and a head portion 90 of the block, the spark plugs being connected to the ignition system to fire alternately.

A carburetor and a drip lubricator 102 are mounted on a top 104 of an enlarged, lower chamber portion 106 of the valve housing casting 68 and respectively supply a combustible mixture, such as, for example, an air and gasoline mixture, and vaporized oil through an opening into a chamber 108 enclosing the timing gears 56 and 60 and the camshaft 62. A conduit 110 leads from an outlet opening 112 in the chamber portion 106 to an inlet opening 114 in the crankcase. A balancing disc 116 keyed to the crankshaft is positioned adjacent the opening 114 and alternately opens and closes the opening 114 in timed relationship to the rotation of the crankshaft. Outlets 120 from the crankcase chamber lead to the interiors of semicylindrical grooves 124 and 126 (FIGURES l and 3) in the block forming cylinders with semicylindrical grooves 128 and 130 in the valve housing casting 68.

Elongated valve sleeves or tubes 132 and 134 control the admission of the air-gasoline mixture to the bore 12 and counterbore 14 through elliptical or flattened ports 136 and 138, respectively. The sleeve 132 is driven by a lifting cam 140 (FIGURES l and 2) on the camshaft 62 and an angular, lifting cam follower 142 rigidly secured on the sleeve 132 by a lowering cam 144 on the camshaft and an angular, lowering cam follower 146 rigidly secured to the sleeve 132. These cams and cam followers positively control the position of the sleeve 132 at all times. As best shown in FIGURE 4, the cam followers 142 and 146 are identical forgings and have ring portions 148 and 150 brazed or welded to a reduced portion 152 of the sleeve 132. A filler sleeve 154 is positioned between the ring portions. The external diameters of the ring portions and the filler sleeve are the same as that of the upper portion of the sleeve 132 and fit closely in the grooves 124, 126, 128 and 130. The sleeve 132 is splined to the member 68 by a key 156 (FIGURE 1) and a splining groove 158. The sleeve 134 is similarly splined to the member 78 and is positively positioned at all times by cams 159 and 160 (FIGURE 2) and cam followers 161 and 162 identical with the cams 140 and 144 and cam followers 142 and 146 but with the cams driving the sleeve 134, of course, being 180 out of phase relative to the cams 120 and 144.

The sleeve 132 has an exhaust port (FIGURE 4) at its upper end, and a plug 172 closes the portion of the sleeve between the port 170 and an outlet port 174 in the sleeve near the upper end thereof. An inlet port 176 is provided in the lower portion ofthe sleeve 132, and a plug 178 closes the bottom of the sleeve 132 Piston rings 180, 182 and 184 are provided at the upper end of the sleeve 132 at opposite sides of the ports 170 and 174. When the port 170 is at the level ofthe port 136 (FIGURE 1), the bore 12 is open to an exhaust pipe 186 secured by capscrews 188 to the top end ofthe block and the member 68. When a land 190 between the rings and 182 is at the level ofthe port 136, the port 136 is closed. When the port 174 is at the levelof the port 136, the port 176 is at the level of the outlet 120 and the interior of the sleeve 132 is open to the bore 12. When the port 176 is at the level of the outlet.l20,.the interior of the sleeve 132 is opened to the crankcase, and when the port '176 is entirely bethe sleeve 134 serving to close off the port 138 when positioned at the level of the port 138. The ports in the sleeve 134 open or close off ports including the port 138 and a lower out-- let in the block 10 corresponding to the outlet 120 and communicating with the lower end of the groove 126. Check valves 196 are in the outlets 120 to permit flow only from the crankcase which permits the ports 176 to be greatly elongated to remove criticality in timing. A check valve 197 in the crankcase end of the passage 100 permits flow only toward the crankcase.

A valving opening 200 (FIGURE 1) provided in balancing disc 116 serves to open the opening 114 near the start of the upward movement ofthe piston 16, and as the piston is moved upwardly it draws the air-gasoline mixture from the carburetor 100 into the crankcase through the chamber 108 which turbulates the mixture. The crankcase is charged throughout substantially the entire upward stroke of the piston 16, and then the disc 116 closes the opening 114 and keeps the opening 114 closed throughout substantially the entire downward stroke ofthe piston 16, and the piston 16 compresses the airgasoline mixture and supercharges the one ofthe bore .12 and counterbore 14 which is in its intake stroke.

The crankcase fits closely around the balancing disc 116 and is small in volume so that the ratio of the displacement of the piston member 20 to the volume of the space below the piston member 20 is high, and the compression ratio is high. To provide high compression during normal operation and adjustment during running and also provide a much lower compression ratio during starting of the engine to ease manual starting, the crankcase is provided with a large volume bore 220, which is closed at one end and open to the exterior of the crankcase at its other end. and a closed filling plug or piston member 222 flts closely in and is slidable along the bore 220. The plug 222 and the crankcase have a spiral bayonet slot interlock serving to lock the plug in any desired adjusted position from a first extreme position completely filling the bore 220 and closing off a passage 224 between the crankcase 116 and the bore 220. The plug 222 is adjustable manually from the exterior, exposed end thereof to any desired position from the above-described. fully inserted position to a second extreme position opening the bore 220 to the crankcase and withdrawn almost completely from the bore 220, the bayonet slot interlock preventing complete withdrawal of the plug from the bore. The plug may be hollow and closed at its ends and serves to open and close the passage 224 with a sleeve valve action, the passage 224 being near the open end of the plug. Preferably the effective combined volume of the plug and the bore 220 when the passage is open is sufficient to reduce the compression ratio of the engine to 5:1 from a 9:1 ratio when the plug 222 closes the port 224. Alternatively, the

plug may be completely closed at both ends and moved between a locked position fully filling-the bore 220 and a position substantially fully opening the bore 220.

OPERATION To start the engine the plug 222 is pulled out of the bore to its extreme withdrawn position, and the user actuates the starter mechanism 54. Then the plug 222 is inserted fully and is locked in a position closing the passage 224 and high compression and high supercharging are in effect. During each two revolutions of the crankshaft 38, each of the two cylinders defined by the bore 12 and counterbore 14 is fired once. At the start of such a cycle, assuming the crankshaft to be at bottom dead center and the piston 20 to have just completed its intake stroke, the outlets 114 and 120 are closed, the valve sleeve 134 is just closing the port 138 (FIGURE 2) and the valve sleeve 132 is just opening the port 136 to exhaust, the outlet 120 and the outlet corresponding to the outlet 120 to the sleeve 134 being closed. The piston 16 then is moved upwardly, the outlet 114 is opened and the piston 116 draws a fresh charge of the combustion mixture of air and gasoline into thecraukcase, the piston member 118 scavenges the bore 12, and the piston member 2 0 compresses further the charge in the counterbore 14. Near the upper end of the stroke the sparkplug 86 is fired, the outlet 114 is closed off from the crankcase and the port 136 is closed off from the port 170. Then as the piston member moves downwardly in its power stroke, the piston member 18 moves downwardly in its stroke. During the first portion of the intake stroke of the piston 18, the piston compresses the charge in the crankcase, and then the valve 132 moves port 174 into communication with the port 136 and simultaneously moves port 176 into communication with the outlet 120. The continued downward movement of the piston members 18 and 20 draws the air-gas mixture under compression into the bore 12. As the crankshaft arrives at its bottom dead center position, the valve 134 opens the port 138 (FIGURE 2) to exhaust, the valve 132 closes the port 136 and the outlet 120 while remaining full of the air-gas mixture under compression, and the disc 116 opens the outlet 114. The piston 16 then moves up, the piston member 20 moving in its scavenging or exhaust stroke and the piston member 18 moving in its compression stroke. Near the upper end of this upward stroke of the piston 16, the port 138 is closed off from exhaust and the sparkplug 84 is fired. The piston member 18 then moves downwardly in its power stroke and the piston member 20 moves downwardly in its intake stroke, the port 138 being opened to the intake port in the sleeve 134 and the lower port in the sleeve 134 opening to the port in the crankcase, the outlet 114 being closed by the disc 116. Then, at the bottom ofthis stroke the port 138 is closed, the port 136 is opened to exhaust and the lower port in the sleeve 134 is closed off from the outlet from the crankcase. The cycle described above then is repeated.

The above-described engine maintains the manifold construction, that is, the sleeves 132 132 and 134, filled at all times with the air-gasoline mixture under the super-charging pressure, positively drive the valves so that no valve float or surging occurs, is simple and light in weight, thoroughly mixes the air and fuel by beating of the cams 140 and 144 and followers 142 and 146 in the valve chamber 108, and is easily started manually under low compression while providing a high compression during normal operation.

EMBODIMENT OF FIGURES 7 AND 8 A four-cycle supercharged engine 300 forming an alternate embodiment of the invention includes a crankcase 302, a block 304, a one-piece dual piston 306, a connecting rod 308, a crankshaft 310, a camshaft 312 and a flywheel 314. A carburetor 316 is connected by a check valve 318 to the sealed interior of the crankcase and a checkvalve 320 connects the interior of the crankcase to the sealed interior ofa valve housing 322. A booster piston or plug 324 serves to adjust the extent of supercharging to obtain optimum supercharging for differences in fuel, speed and conditions of operation. The booster piston 324 may be adjusted manually by a handle 325, either while the engine is running or while the engine is stopped, to any desired position between a full supercharging position and a minimum supercharging position, the latter being such as to lower the compression ratio to a value at which the engine can be easily cranked manually. The booster piston 324 is connected by long pitch spiral gear portions 330 and 332 to a follower rod 334 splined by member 336 to base portion 338 of the crankcase 302. The follower rod is slidable in a bushing 340 and is urged by a spring 342 upwardly into engagement with a cam 344 keyed to the crankshaft 310. The spring bears against a spring seat 346 carried by the hollow base 338 of the crankcase and against the piston 324 which is slidable in vertical bore 348 in the base 338. The handle 325 is connected to a sleeve 350 which is splined to the piston 324 by one or more pins 352 slidable in bores in the sleeve 350. The handle is movable along a peripheral slot 342, and a releasable locking clamp 356 carried by the handle is operable to lock the handle in the desired adjusted position.

The booster piston 324 is driven 180 out of phase from the piston 306 so that the piston 324 moves down when the piston 5 justment of the piston 324 relative to the crankcase, in which position the piston 324 is flush with the bottom of the crankcase. The piston 324 is adjustable on the follower rod from this upper extreme position to a lowermost, engine-starting, upper position in which the piston 324 is well down on the follower rod to greatly increase the effective volume of the crankcase to reduce the compression ratio. The piston 324, of course. also is adjustable by the handle 325 to intermediate positions to obtain optimum supercharging for different speeds and conditions of operation of the engine. Also, with the piston 324 touching the sleeve 358, the piston may be turned further to pull the follower rod 334 down completely out of the path of the cam 334 so that the piston does not move during operation ofthe engine so that no boosting effect is provided. Also, the rod may be held in only a partially withdrawn position by the piston 324 to provide shortened stroke of the piston 324.

Valve pistons 370 and 372 reciprocal in valve sleeves 374 and 376 fixed in parallel positions in the block 304 control both intake and exhaust of ports 378 and 380 to chambers 382 and 384. The valve pistons are connected to rods 386 and 388 urged by springs 390 against identical cams 392 and 394 keyed to the camshaft 312 in positions out of phase. The springs seat on spider-like seats 396 and 398 fixed to the sleeves 374 and 376 and to the rods 386 and 388. When one of the pistons 370 and 372 is above its port 378 or 380, that port is connected to intake. Whenever one of the pistons 370 and 372 is below its port 378 or 380, that port is connected to exhaust. Whenever one of the pistons 370 and 372 is in a position blocking its port 378 or 380, as illustrated by the position of the piston 372 in FIGURE 7, with rings 400 bracketing the port, the port is sealed.

A thick gear 405 is engaged by a timing gear 402 on the camshaft 312 (FIGURES 7 and 8). The gear 402 is adjustable lengthwise and rotatively relative to the driving gear 405 by a manually adjustable lever 404 connected by a fork 406 to a collar 408 fixed to the gear 402. A very long pitch spiral gear member 410 pinned to the camshaft turns in complementary internal spiral gearing 412 in the gear 402 to turn the shaft 312 slightly relative to the gear 402. The gear 402 meshes with the gear 405 keyed to the crankshaft. By adjusting the camshaft relative to the gear, the timing is, ofcourse, adjusted. The handle or lever 404 is secured by a frictional clamp 414 to hold it in the desired condition ofadjustment.

Wedge-like, spiral upper faces 420 and 422 of equal area of circular head 424 and annular head 426 of piston members 428 and 430, respectively, face planar heads 432 and 434 of the cylinder 304. Spark plugs 436 and 438 are adjacent the lowermostportions of the wedge-like heads 420 and 422 and initially ignite the air-gasoline mixtures in the deepest portions of the chambers defined by the wedge-like heads 432 and 434 and the heads 424 and 426. This causes combustion to take place with a swirling or spiraling effect, which minimizes detonation or pinging.

For best operation of the engine 300, the volume of the volume of the intake manifold, which includes the camshaft chamber, should be and is at least as great as the displacement of each of the piston members 428 and 430 of the piston 306. This forms, with the check valve 320, a large volume reservoir of the combustible mixture under supercharged pressure, and this stored high pressure mixture is available immediately when either the port 378 or the port 380 is opened to rapidly fill the upper end portion of the cylinder supplied by that port. Then, while the piston member moves on down in its intake stroke. the piston 306 supercharges the mixture in the crank case and forces it into the camshaft chamber and the cylinder.

EMBODIMENT OF FIGURES 9 T014 A four-cycle, supercharged engine 500 includes a crankcase 502, a block 504, a one-piece, dual or stepped piston 506, a connecting rod 508, a crankshaft 510 and a camshaft 512. The piston 506 includes an upper piston member 514 and a lower piston member 516, both of the same area, and, of course, the same displacement into their respective cylinders 536 and 540 but with a displacement into the sealed crankcase area of twice that of either pistons displacement into its respective cylinder. Spark plugs 518 and 520 are fired on alternate revolutions of the piston. A check valve 522 admits air to the otherwise sealed interior of the crankcase on each upward stroke ofthe piston. A check valve 524 admits the air from the crankcase to a camshaft chamber 526 whenever air in the crankcase is under a higher pressure than is the air in the camshaft chamber 526 as occurs on each downward stroke of the piston 506. Since the displacement of the piston 506 into the crankcase on each downward stroke is double the intake capacity of the cylinder then being charged, compression of the air or air-fuel mixture is maintained in the chamber 526. Whenever a port 528 or a port 530 in the valve sleeve 532, which is closed at its upper end and open at its lower end, is open to a port 534 to the cylinder 536 or a port 538 to the cylinder 540, the compressed air in the camshaft chamber flows through a venturi portion 542 of a carburetor 544 to draw gasoline through a jet 546 to form a combustible mixture. This compressed mixture flows on through the sleeve and ports in the sleeve and cylinder to supercharge the cylinder. A slotted throttle butterfly valve 548 also is provided, and a line 550 supplies the pressure of the air in the camshaft chamber 526 to the top of the float chamber in the carburetor which is supplied with gasoline by a line 552 from a fuel pump.

Fast acting, three lobe, constant diameter cams 560 and 592 (FIGURES 9, l l and 12) are rigidly pinned to a camshaft 562 mounted in airtight, sealed bearings 564 in the housing of the camshaft chamber. The camshaft 562 is driven by gearing 566 from the crankshaft 510 at half the speed of the crankshaft. The cams 560 and 592 are approximately 90 apart and are revolved in square follower openings 568 in connecting rods 570 to rapidly open and close the ports 534 and 538 and ports 584 and 586, respectively. The action of cam 560 is such that, as the port 528 approaches the port 534, a lobe 572 moves the sleeve 532 rapidly upwardly to rapidly open the port 534. Then, there is a dwell period during the intake stroke of the piston member 514, and as this intake stroke nears its end, a

lobe 574 of the cam rapidly moves the sleeve 532 downwardly to rapidly close the port 534. Both ports 534 and 538 then remain closed until the intake stroke ofthe piston 516 is about to start, at which time the lobe 572 rapidly moves the sleeve 532 down to open the port 530 to the port 538. At the end of the intake stroke of the piston member 516, the lobe 574 moves the sleeve 532 rapidly upwardly from its lowermost position to rapidly close the port 538. A third lobe 576 of the cam 560 keeps the cam always in engagement with all four sides of the square follower opening 568. The point ofthe lobe 572 is at the extreme offset position from the axis of rotation of the camshaft 562 and the lobes 574 and 576 are equidistant from a line from the lobes 572 to the axis of rotation of the crankshaft. The lobes are spaced 120 apart and are separated by identical rounded portions 580. Piston rings 581 are provided.

An exhaust valve sleeve 582 FIG. 10) is open to exhaust at its upper end and is closed at its lower end. Exhaust ports 584 and 586 are rapidly opened and closed by ports 588 and 590 in the sleeve 582. The sleeve 582 is moved by a connecting rod and follower 591 and the three lobe, constant diameter cam 592 (FIGURE ll) locked rigidly to a crank portion 594 ofthe camshaft 562 approximately 90 away from a crank portion 596 mounting the cam 560. The cam 592 also has lobes corresponding to and numbered the same as the lobes of the cam 560.

The combined volume ofthe camshaft chamber 526 and the sleeve 532 is as great as the displacement of either piston member 514 or 516. This makes a large reservoir or supply of gas under the supercharging pressure available immediately when either port 534 or 538 is opened for very fast initial charging of the cylinders.

To vary the degree of supercharging, a hollow, partitioned plug 600 (FIGURES 9, 13 and I4) is fitted closely and rotatably in bore 602 in the crankcase 502. The rotative position of the cylinder 600 is determined by the combined action of a rod 604 coupled to the throttle control and by a rod coupled to a known pressure responsive mechanism responsive to manifold pressure. The rods 604 and 606 are coupled to a lever 608 pivotal on a link 610 connected to a crank 612. The rod 604 is moved upwardly when the throttle is moved in an opening direction and the rod 606 is moved upwardly when the manifold pressure is decreased. When either rod'604 or 606 is moved upwardly, the crank 612 is swung counterclockwise to turn the plug 600 counterclockwise. Movement in this direction successively moves step-like slots 614 to 617 from positions open to a slot 620 to positions closed thereto. This step by step closes off compartments 624 to 627 of the plug from the interior of the crankcase to reduce by steps the volume of the crankcase to reduce by steps the volume of the crankcase chamber, thereby increasing the extent of supercharging. The compartments 624 to 627 are sealed from each other by transverse partitions 630.

While the supercharged engine 500 is described above with the carburetor 544 positioned in the intake manifold with only air supplied through the check valve 522, if desired, the carburetor may be removed from the intake manifold and placed in the line leading to the check valve 522 to supply air-fuel mixture to the crankcase rather than directly to the intake manifold.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

I claim:

1. In a supercharged engine,

housing means including a cylinder portion, a crankcase chamber and a camshaft chamber,

valve means connecting the crankcase chamber and the camshaft chamber,

a piston reciprocable in the cylinder portion,

a camshaft rotatable in the camshaft chamber,

a crankshaft rotatable in the crankcase chamber,

connecting rod means connecting the piston and the crankshaft,

valve means operable by the camshaft for connecting one of said chambers periodically to the head end of the cylinder portion,

and carburetor means for supplying an air-gasoline mixture to the other ofsaid chambers.

2. The supercharged engine of Claim 1 wherein the valve means includes a tubular valve member receiving the airgasoline mixture at one end from the crankcase and having a lateral port adapted to connect the valve member to the head end of the cylinder portion when the valve member is moved to an intake position.

3. The supercharged engine ofClaim 2 wherein the housing means includes a sleeve portion fixed relative to the housing means and mounting the tubular valve member movably therein,

the sleeve portion having a port connecting the interior thereof to the head end of the cylinder portion and also having an inlet port connecting the valve member to the crankcase.

4. The supercharged engine of Claim 2 including a filler plug normally fully inserted into the crankcase'to reduce the effective volume of the crankcase and adjustably withdrawable from the crankcase to increase the effective volume thereof.

5. The supercharged engine of Claim 1 including a filler plug adjustably mounted by the housing means between a normal position in which the crankcase has a predetermined effective volume and a second position withdrawn from the crankcase to increase the effective volume of the crankcase.

6, In a supercharged engine,

engine housing means including a crankcase and a cylinder having a head end and a crankcase end open to the crankcase,

a piston reciprocable in the cylinder for compressing gas in the crankcase during movement toward the crankcase,

a tubular guide member having at one end a lateral inlet port connected to the crankcase and also having an exhaust port at the other end thereof and provided with a third port located between the inlet and exhaust ports and connecting the interior thereof to the head end of the cylinder,

valve sleeve closed at opposite ends and slidable in the tubular guide member,

the valve sleeve having an inlet port near one end adapted to be connected to the inlet port of the tubular guide member and also having a lateral outlet port near the other end thereof adapted to be connected to the third port,

and camshaft means for moving the valve sleeve between an intake position in which the sleeve connects the inlet port thereof to the inlet port of the guide member and closes the exhaust port from the third port of the tubular guide member and the lateral outlet port is open to the third port, an exhaust position in which the valve sleeve connects the exhaust port to the third port, closes the outlet port from the third port and closes the inlet port of the sleeve from the inlet port ofthe tubular member and a third position in which both the inlet port of the valve sleeve and the outlet port thereof are closed.

7. In a supercharged engine,

housing means including a crankcase and a cylinder having a head end and a crankcase end open to the crankcase and also being provided with a tubular guideway open at one end thereof to the crankcase and open at the other end to exhaust,

the housing means having a cylinder port between the head end ofthe cylinder and the tubular guideway,

a piston reciprocable in the cylinder,

a crankshaft in the crankcase,

a connecting rod connecting the piston and the crankshaft,

a tubular valve member fitting closely and slidably in the guideway and open at the end thereofnearer the crankcase and having a lateral exhaust port near the other end, a lateral supply port between the exhaust port and the end nearer the crankcase and means closing the portion of the valve member between the exhaust port and the supply port,

valve means between the crankcase and the guideway,

carburetor means for supplying an air-gasoline mixture to the crankcase,

and cam means for moving the valve member between an exhaust position in which the exhaust port of the valve member is connected to the cylinder port and an intake position in which the supply port is connected to the cylinder port.

8. The supercharged engine of Claim 7 wherein the valve means includes a check valve permitting flow from the crankcase to the guideway.

9. The supercharged engine of Claim 1 wherein the valve means includes a tubular passageway having a port to the cylinder and a valve piston movable from an intake position opening the port to the crankcase, an exhaust position opening the port to exhaust and a third position closing the port.

110. In a supercharged engine,

a crankcase,

ill

a cylinder,

a piston closing the cylinder from the crankcase and reciprocated in the cylinder toward and away from the crankcase,

means for supplying gas to the crankcase when the piston is moved away from the crankcase,

valve means for supplying gas from the crankcase to the cylinder when the piston is moved toward the crankcase,

a compartmental chamber connected to the crankcase,

and means for selectively connecting compartments of the chamber to the crankcase.

11, The supercharged engine of Claim 10 wherein the chamber comprises a hollow cylindrical plug having compartments therein and stepped openings to the compartments, and means for rotating the cylinder to selectively connect predetermined ones of the compartments to the crankcase.

12. The supercharged engine of Claim 11 including a lever for actuating the means for rotating the cylinder,

throttle control means connected to the lever for actuat-- ing the lever,

and manifold pressure responsive means connected to the lever for actuating the lever.

13. in a supercharged four-cycle engine,

a crankcase sealed to permit compression,

a cylinder of stepped configuration to provide two cylinder chambers of equal volumes,

a piston of stepped configuration closing each of the cylinder chambers from each other and from the crankcase and whose displacement into the crankcase sub stantially exceeds the displacement of the piston into either cylinder chamber,

a sealed intake manifold chamber sealed to permit compression and having a volume greater than that of either cylinder chamber,

valve means to allow air to flow into the crankcase only from outside the engine when the piston is moving away from the crankcase and to flow only into the scaled intake manifold chamber when the piston is moved toward the crankcase,

valve means to connect the intake manifold chamber alternately with the cylinder chambers when the piston is moved toward the crankcase,

and carburetor means for mixing gas with the air at a point along the path of the air from outside the engine to the cylinder chambers 14. ln a supercharged engine,

a crankcase,

a cylinder,

a piston slidahle in the cylinder and varying the volume of the crankcase,

carburetor means supplying the crankcase,

valve means connecting the crankcase to the head end of the cylinder.

and plug means adjustable in the crankcase to vary the volume thereof and including a cylindrical guideway open at an outer end to atmosphere and open at an inner end to the crankcase, an idler piston movable in the guideway between an inner position in which the head end of the idler piston forms a continuation of the walls of the crankcase and an outer position in which the portion of the guideway adjacent the crankcase is open to the crankcase, and drive means driving the idler piston approximately l out ofphase relative to the first-mentioned piston,

the drive means including cam means on the crankshaft, follower means on the idler piston and engaging the cam means and means biasing the idler piston toward its inner position.

15. In a supercharged engine,

a crankcase,

a cylinder,

a piston slidable in the cylinder and varying the volume of the crankcase,

carburetor means supplying the crankcase,

valve means connecting the crankcase to the head end of the cylinder,

and plug means adjustable in the crankcase to vary the volume thereof and including a cylindrical guideway open at an outer end to atmosphere and open at an inner end to the crankcase, an idler piston movable in the guideway between an inner position in which the head end of the idler piston forms a continuation of the walls of the crankcase and an outer position in which the portion of the guideway adjacent the crankcase is open to the crankcase, drive means driving the idler piston approximately 180 out of phase relative to the first-mentioned piston, and manually operable means for adjusting the inner position of the idler piston.

16. In a supercharged engine,

a cylinder, an intake chamber,

intake valve means for admitting a combustible mixture I to the cylinder from the intake chamber,

a crankcase,

gas supply means for supplying a combustible mixture,

a piston separating the cylinder and the crankcase and movable in the cylinder toward and away from the crankcase to effect a displacement of a predetermined volume,

v second valve means for connecting the gas supply means to the crankcase when the piston is moved away from the crankcase and closing the gas supply means from the. crankcase when the piston is moved toward the crankcase,

third valve means for connecting the crankcase to the intake chamber when the piston is moved toward the crankcase and closing the crankcase from the intake chamber when the piston is moved away from the crankcase.

the intake chamber having a volume at least substantially as great as said predetermined volume,

the intake chamber comprising a manifold containing the first valve means and a camshaft chamber connected to the crankcase through the third valve means and through which the combustible mixture flows to the manifold,

and camshaft means in the camshaft chamber for actuating the first valve means and for turbulating the combustible mixture as it flows through the camshaft chamber to the manifold. 

